Related Experiment Videos
Transcription factor as a topological homeostat
Georgi Muskhelishvili1, Andrew Travers
1Max Planck Institute for terrestrial Microbiology, Karl-von-Frisch Strasse, D-35043, Marburg, Germany. muskheli@mailer.uni-marburg.de
Frontiers in Bioscience : a Journal and Virtual Library
|November 29, 2002
Summary
Prokaryotic proteins like FIS regulate gene expression by controlling DNA supercoiling. This study shows FIS optimizes gene expression by linking global DNA topology to local promoter activity.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Prokaryotic chromatin proteins act as global transcriptional regulators.
- Some proteins modulate topoisomerase activity, affecting DNA superhelicity.
- The interplay between global DNA topology and local promoter effects is under-explored.
Purpose of the Study:
- To investigate the relationship between global DNA topology and local promoter effects of chromatin architectural proteins.
- To explore how FIS (Factor for Inversion Stimulation) influences DNA supercoiling and gene expression.
Main Methods:
- In vitro studies of FIS binding to supercoiled DNA.
- Analysis of FIS's effect on DNA gyrase activity and superhelicity.
- Examination of FIS's role in regulating stable RNA promoter activity.
Main Results:
- FIS reduces DNA gyrase activity, counteracting superhelicity increase during growth.
- In vitro, FIS binding to supercoiled DNA forms branched structures and apical loops.
- FIS acts as a topological homeostat at stable RNA promoters, maintaining supercoiling for activity.
Conclusions:
- FIS coordinates global and local DNA architecture.
- This coordination optimizes gene expression by directing supercoiling energy to specific sites.
- FIS links global DNA topology regulation to promoter-specific functions.